Spirit level

Abstract

The spirit level, for use by carpenters, bricklayers or the like has a body comprising an elongate extrusion with at least one flat supporting edge 3. An outer rotatable member 10 is rotatably mounted in a transverse circular aperture in the elongate extrusion, and an inner rotatable member 11 is rotatably mounted in a transverse circular aperture in the outer rotatable member and coaxial therewith. A bubble tube 14 is secured to the inner rotatable member in fixed orientation relative thereto, such that rotation of the inner rotatable member effects coarse rotation of the bubble tube and rotation of the outer rotatable member (together with the inner rotatable member) effects fine rotation of the bubble tube. The angle can be measured by placing edge 3 on a test surface, successively rotating inner member 11 and outer member 10, and reading off the resulting angles on coarse scale 19 and fine scale 24.

We claim: 
     
       1. A spirit level for use by carpenters, bricklayers or the like, which comprises: (a) an elongate body having a flat supporting surface along at least one lateral edge thereof, said body having a transverse circular aperture therethrough and a fine angular scale;   (b) an outer rotatable member rotatably mounted in said aperture, said outer rotatable member having an elongate pointer portion interacting with said fine angular scale and a transverse circular aperture therethrough coaxial with the aperture in said elongate body;   (c) an inner rotatable member rotatably mounted in the aperture in said outer rotatable member; and   (d) a bubble tube secured to said inner member in fixed orientation with respect thereto; whereby rotation of said inner rotatable member effects coarse adjustment of the orientation of said bubble tube relative to said lateral edge, and rotation of said outer rotatable member with said bubble tube in fixed orientation with respect thereto effects fine adjustment of the orientation of said bubble tube relative to said lateral edge.   
     
     
       2. A spirit level according to claim 1, wherein said inner rotatable member carries a first pointer which indicates the longitudinal axis of said bubble tube. 
     
     
       3. A spirit level according to claim 2, wherein a coarse angular scale is provided around the aperture in said outer rotatable member to indicate the angle between the lateral edge of said body and the longitudinal axis of said bubble tube. 
     
     
       4. A spirit level according to claim 3 wherein said inner rotatable member is rotatably movable between a plurality of predetermined positions, each defined by stop means. 
     
     
       5. A spirit level according to claim 4 wherein said inner rotatable member is rotatable through 360. 
     
     
       6. A spirit level according to any of claims 1 or 5, wherein said elongate pointer is arranged to extend, in one position, parallel to said lateral edge. 
     
     
       7. A spirit level according to claim 3, wherein said inner rotatable member carries along with said first pointer three additional pointers all evenly spaced around the periphery of said member, said three additional pointers adapted to be able to interact with said coarse angular scale. 
     
     
       8. A spirit level according to claim 1, wherein said outer rotatable member is constrained from rotation by more than a predetermined amount, such as about 10 degrees. 
     
     
       9. A spirit level according to claim 1, wherein said elongate body comprises a unitary extrusion. 
     
     
       10. A spirit level according to claim 1, which includes at least one additional bubble tube. 
     
     
       11. A spirit level according to claim 10 wherein said at least one additional bubble tube includes first additional bubble tube having an axis fixed substantially parallel to said lateral edge and a second additional bubble tube having an axis fixed substantially perpendicular to said lateral edge. 
     
     
       12. A spirit level according to claim 1, wherein said outer rotatable member transverse circular aperture has a diameter and said elongate pointer portion has a length approximately greater than said diameter.